Two-speed ratchet devices



3 Sheets-Sheet l Filed Nov. 2s, 1953 Trai FIGB April 9, 1957 c. D. P.sMALLPElcE TWO-SPEED RATCHET DEVICES 3 Sheets-Sheet 2 Filed Nov. 23,1953 FIGA.

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April 9 1957 C. D. P. sMALLPElcE 2,787,912

TWO-SPEED RATCHET DEVICES Filed Nov. 25, 1953 3 Sheets-Sheet 3 TWG-SPEEDRA'CHET DEVICES Cosby Donald Philipps Smallpeice, Swanwick Shore, nearouthampton, England Application November 23, 1953, Serial No. 393,914

Ciaims priority, application Great Britain December 5, 1952 6 Claims.(Cl. 74-142) States Patent A form( of ratchet mechanism having tworatios, and one which does not involve the use of gearing.

Though not in any way limited in this respect, the invention isparticularly of use for ratcheting a winch in yacht racing, the highspeed being used for initially taking in the sheet rapidly and the lowspeed for electing the final tautness of the sheet.

According to the invention, a ratchet mechanism has an operating leverwhich passes across the axis of the ratchet (when the lever is movedfrom one extreme angular position to the other) or of an equivalent partand of which the fulcrum is off-set from though parallel to the axis ofthe ratchet so that a projection on the lever on one side of the axiswill enable an angular movement to be given to the ratchet which is lessthan that of the lever, whereas a projection on the other side of theaxis will enable an angular movement to be given to the ratchet which isgreater than that of the lever, thereby providing two ratios between thelever and ratchet.

The ratchet mechanism, of course, has means for selectively moving theprojections into the operative positions, and, preferably, selection iseffected by the movement of the operating lever in a direction radial toits fulcrum.

In the accompanying diagrammatic drawings:

Figure l is a schematic sectional elevation of a winch having applied toit a simple form of ratchet mechanism according7 to the invention, thesection being taken on the line -l of Figure 2;

Figures 2 and 3 are sectional plans on the broken line 2 2 of Figure lshowing the high speed projection in operative engagement in Figure 2,and the low speed projection in operative engagement in Figure 3;

Figure 4 is a schematic sectional elevation of a winch fitted with apreferred form of ratchet mechanism according to the invention; and

Figures 5 to 8 are all sectional plan views taken approximately on thebroken line 5 5 of Figure 4.

Referring first to the construction of Figures 1 to 3, the winch 1t istast with a stub shaft 12 which is formed integrally with or otherwisesecured to a ratchet 13, shown as being in the forrn of a toothedratchet wheel. The winch is journalled, for example, as indicated at l5,on a cover plate i7 for the ratchet, the cover plate coacting with astationary base 18 which has on one side a slot 19 to receive theoperating lever 20 and limit the angular movement thereof.

In Figures 1 to 3 the operating lever 20 i's shown as being slidinglyfulcrumed on a pin 22 carried by the base 18 and working in a radialslot 23 of the arm. Spaced apar-t from one another along the length ofthe arm, and on opposite sides of the ratchet (with the axis of whichthe fulcrum pin 22 is parallel though eccentrically arranged), are twoprojections 26, 27 adapted to coact with the teeth 28 of the ratchetdependently upon the axial position of the operating lever. Obviously,in practice, these projections might taire the form of spring-pressedpawls. 29 is a non-return spring-pressed pawl carried by the cover plate17.

With the parts in the positions shown by Figure 2,

the angular movement given to the ratchet when thei operating lever ismoved from one extreme angularposition to the other (it is shown inFigure 2 and in Figure 3 as passing diametrically across the ratchet--i.e., in an intermediate position) will be greater than that of the lever.In the position of Figure 3, however, the angular movement to be givento the ratchet will be less than that given to the lever.

In the construction of Figures 4 to 8, the winch 31 is journalled on astub shaft 32 which, in this case, is formedl integrally with a coverplate 33 secured to a stationary base 34 by screws 35. The lower end ofthe winch is ifast with a ring 37 with which coact a set of rollers 384of a free-wheel or overrunning clutch having a ratchet 39 in the form ofa central cam disc which is journalled on a spigot 4%. Fast with thespigot 40 is another-cam ring 42 coacting with the ring 37 throughanother set of free-wheel rollers 43. rille ratchet 39 has a hole 44a toreceive a driving pin 44 fast with a rotatable member in the form of aplate 45' which is shown as being angu. larly movable about the axis ofthe winch, the pin 44 being able to work in an arcuate slot 46 providedin the cover plate 33.

Only the operative end o the operating lever 48 is shown in Figures 4 to8, and it will be understood that the lever may be continued as far asdesired for manipulation by an operator. The operative end of the leveris slidably carried in a diametrical slot of a trunnion 50 which in turnis angularly movable in a recess 51 of the stationary base provided forthe purpose, the axis of the trunnion being parallel to, i. e., oit-setfrom, the axis of the winch. The plate 45 has two recesses provided inits periphery which, when the operating lever is in the positions ofFigures 5 and 7, can selectively receive the adjacent projections orpins 53, 54 which are fast with the lever and mounted on a centre linethereof.

Thus, with the high speed pin 54 engaged with the plate 45, as shown byFigure 7, the plate can be turned to the position shown in Figure 8 fora given angular movement of the lever as dened by a slot (like the slot19 of Figures 2 and 3) in the adjacent wall of the base, while the pin44 moves along the arcuate slot 46, thus rapidly to turn the winchthrough the ratchet 39-i. e.,

v through the roller free-wheel including the rollers 38.

On the return stroke of the operating lever the free-wheel including therollers 43 prevents rotational movement of the winch.

When, however, the load becomes excessive, the operating lever is slidinwardly (Figure 5) to bring the slow speed pin 53 into drivingengagement with the plate 45, and the operating lever can then be movedinto the position shown by Figure 6. A comparison of Figures 6 and 8 asregards the movement of the pin 44 along the arcuate slot 46 indicatesthe gear ratio involved, i. e., the ratio of the distances of the pins53, 54 from the pivotal axis of the tiunnion 50 when the pins are in theoperative position.

The extension 56 on the plate 45 is for keeping the associated pin 54from running over the end of the plate.

It will be understood that the ratchet 39 of the roller free-Wheelcould, if preferred, be a toothed ratchet wheel coacting with a pawl. Inlike manner, the holding roller i A Fatented Apr. 9, 1957-"-4 3free-wheel (37, 42 and 43) could be replaced by a pawl coacting with atoothed ratchet wheel.

In the particular example the ratchet 39 and the rotatable member 45 arecoaxial with one another, but they need not be. In the latter case theoperating lever might not pass across the axis of the ratchet when movedbetween its extreme positions, but it would, of course, pass across theaxis of the rotatable member 45. The advantage of having a rotatablemember which is not concentric with the ratchet is that it provides ameans of altering the ratio between the lever and ratchet.

What I claim as my invention and desire to secure by Letters Patent ofthe United States is:

1. A two-speed ratcheting mechanism including a oneway driving devicehaving a driving element, an operating lever movable about its fulcrum,means limiting the movement of the lever between two extreme angularpositions, said fulcrum being olf-set from but parallel to the axis ofsaid driving element and arranged so that during movement of the leverbetween its extreme angular positions the lever will pass across theaxis of the driving element, and projections on the lever which areselectively movable into operative positions to drive said drivingelement at different speed ratios by sliding movement of the lever alongits longitudinal axis.

2. A ratcheting mechanism, according to claim l, in which theprojections are fast with said lever to be carried into their operativepositions dependently upon the direction of the longitudinal movement ofthe lever.

3. A ratcheting mechanism comprising a one-Way driving device having arotatable driving element, an operating lever, a fulcrum for the leverhaving an axis which is off-set from but parallel to that of the drivingelement, means connecting the lever for sliding motion along itslongitudinal axis and relatively to its fulcrum, a plate mounted forrotation about the axis of the driving element andinterposed between thelatter and the lever, a pin fast with said plate and engaged with a holein the driving element, and longitudinally spaced projections on saidlever adapted to selectively engage oppositely disposed recesses of saidplate in the respective longitudinal positions of the lever to enablethe driving clement to be turned at different speed ratios.

4. A ratcheting mechanism, according to claim 3, in which a cover isinterposed between said plate and the driving clement, the covercoacting with a stationary base to enclose the fulcrurn of the lever andsaid rotatable plate, said stationary base having in it a slot which isarcuate about the axis of the driving element to receive said pin.

S. A ratcheting mechanism, according to claim 3, and in which theone-way driving device is of the roller freewheel type, having an outerring engaged by rollers coacting with the driving element, incombination with a one-way brake device of the roller type and sharingthe same outer ring.

6. A ratcheting mechanism, according to claim 3, in which the fulcrumfor the operating lever includes a disc rotatable about a fixed axis,the lever being slidable in a diametrical slot of the disc duringsliding motion of the lever along its longitudinal axis.

References Cited in the tile of this patent UNITED STATES PATENTS1,135,655 Beemer Apr. 13, i915 1,985,406 Galkin DCC. 25, 1934 FOREIGNPATENTS 458,676 Germany Apr. 17, 1928

